Eleven years ago, a shiny silver Boeing 727 airliner took off from Luanda, Angola, and became one of the few commercial jetliners to vanish and never be found.

Massive jet airplanes disappear more often in fiction than in real life, but it does happen. In 1979, a Boeing 707 with six people aboard was lost in the Pacific Ocean after leaving Tokyo. And dozens of smaller planes have gone missing and never been located.